1. Field of the Invention
The invention relates to a piston for an air pump, and more particularly to a piston for an air pump to enhance the sealing effect, to prevent deformation of a valve and to reduce operating noise.
2. Description of Related Art
An air pump for inflating tires or airbeds generally comprises a motor, a piston cylinder and a piston. The piston reciprocates in the piston cylinder by operation of the motor, and the piston can compress the air in the piston cylinder to high pressure gas for inflation.
The piston has a piston seat and an elastic flap. The piston seat is mounted at a top end of the piston and has a through hole. The elastic flap is mounted on a top end of the piston seat and covers the through hole. When the piston is driven by the motor, the airflow impacts the elastic flap to lift the elastic flap from the through hole, and then the airflow flows through the through hole into the piston cylinder. When the piston is driven by the motor at the next time, and the airflow will be pushed to flow out the piston cylinder.
The conventional piston has the following disadvantages:
1. The elastic flap is mounted on the piston seat by a rivet, so the combination between the elastic flap and the piston seat is complex. Moreover, the elastic flap becomes warped and deformed when the air pump has been used for a period. Then, a gap is formed between the elastic flap and the piston seat or the elastic flap does not hermetically cover the through hole of the piston seat. Thus, the working efficiency of the piston is poor.
2. The elastic flap is metal and causes a noise when the elastic flap returns to cover the through hole of the piston seat.
3. The material cost of the elastic flap is high.
To overcome the shortcomings, the present invention provides a piston for an air pump to obviate the aforementioned problems.